Does the Leopard VPN Client Encrypt the Login?

I am going on vacation and will be connecting to my university's VPN in order to create a secure tunnel when using public WiFi. I just wanted to know, does the Mac OSX VPN client encrypt the actual login to the VPN? Also, in general is using the OSX VPN client as secure as using say, the Cisco client that my university makes available for download?

Well I am using L2TP over IPSec. I heard from someone though, that whether or not the login credentials are encrypted depends on the VPN client. Does the OSX Leopard VPN client encrypt the login credentials? Also, if you know does the VPN client on the iPhone/iPod Touch encrypt the login credentials?

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